Acetone-formaldehyde reaction product corrosion inhibitor



United States Patent Qfitice 3,%5,l84 Patented Nov. 20, 1962 3,965,184ACETONE-FORMAEDEHYDE REACTEQN PRODUCT CGRRGSION IYHEBITGR Mortimer T.Harvey, South Orange, N.J., assignor to illarvel Research Corporation, acorporation of New ersey No Drawing. Filed Sept. 27, 1957, Ser. No.686,591 1 (ilaim. (Cl. 252146) The present invention relates generallyto the art of cleaning metal surfaces with pickling agents and to theart of electroplating on metal surfaces, and the present inventionrelates more particularly to the protection of metal surfaces againstthe action of pickling agents during the cleaning of metal surfaces andagainst the action of electrolytes during the electroplating of metalsurfaces.

An object of the present invention is to provide a composition ofchemicals for use in the cleaning of metal surfaces and inelectroplating on metal surfaces, which composition is eifective in itsprimary function and is also effective in protecting the metal surfaceagainst any deleterious action of the cleaning agent itself on the metalbeing cieanedand against any deleterious action of the electrolyte onthe metal on which plating is to be done or is being done in anelectroplating solution.

Another object of the present invention is to provide a composition ofchemicals comprising a cleaning agent and a restraining agent orinhibitor for cleaning purposes and for electroplating uses in which theinhibitor protects metal to be cleaned, and metal on whichelectroplating is to be or is being done, against any deleterious actionof the cleaning agent or of the electrolyte in electroplating operation.

Another object of the present invention is to provide an electroplatingsolution which is advantageous to the obtaining of good adherencebetween metal deposited and the metal surface on which the depositedmetal is laid during electroplating operation, said electroplatingsolution comprising (1) an acidic agent and (2) an inhibitor capable ofpreventing deleterious action of said acidic agent with respect to themetal surface onto which electroplating is being done.

Another object of the present invention is to provide a solution forelectroplating comprising (1) an acidic electrolyte and (2) an inhibitorwhich is continuously opera- .tive during electroplating process -torestrain deleterious action of said acidic electrolyte with respect tothe surface onto which electrodeposition is being done.

Another object of the present invention is to provide a combination ofan acidic material and an inhibitor for use in electroplating baths inwhich the inhibitor in which .the latter acts continuously andsubstantially uniformly over the surface onto which metal is to bedeposited wherebythe deposition is made continuously uniform and therebyhigher current densities can be economically used in .theelectrodeposition and whereby good adherence is obtained between themetal onto which plating is done and the metal deposited thereon andfurther between the successive increments of the deposited metal.

It is also an object of the present invention to provide a compositionof chemicals comprising (1) an acidic electrolyte and (2) an inhibitorfor use in the flash electroplating of successive layers of differentmetals on a metal base whereby the deposited metals are protectedagainst deleterious action of electrolytes used in the electrodepositionof succeeding metals; for example, as in the successive deposition ofcopper, nickel and chromium on steel.

I have discovered that certain water soluble ketonealdehyde reactionproducts, e.g., acetone-formaldehyde reaction product, when included inpickling baths, in electroplating baths and in primary and secondarybatteries have the property of cutting down the action of hydrogen atthe surface of metal without limiting the effectiveness of electrolytesin the removal of oxides, greases and other undesirable materials inpickling operation and without limiting the electrolytic actionsoccurring in electroplating baths and in primary and secondarybatteries, and I have discovered further that the presence of said watersoluble ketone-aldehyde reaction products in such said baths andbatteries enhances the desired operation or action.

I have also discovered that the presence of water solubleketone-aldehyde reaction products in electroplating baths cuts down theentrainment of metals and metal compounds by vapors which pass out ofsaid baths when the latter are hot.

Following are examples of (A) Water soluble ketonealdehyde reactionproducts, (B) pickling baths, (C) electroplating baths or solutions, (D)primary battery mixtures and (E) electrolytes for use in secondary orstorage batteries.

For General Examples (A) reference is made to the US. Patent No.2,683,133 which describes water soluble ketone-aldehyde reactionproducts, and the methods for making them, suitable for use in thepractice of the present invention.

More particular Examples A are as follows.

EXAMPLE Al (One Mole of Acetone With Four Moles of Formaldehyde) 300lbs. acetone 1700 lbs. formaldehyde (37% concentration) 25 lbs. .NaOH in60 lbs. Water The caustic soda-water solution was divided into fourequal portions. The unit was loaded with acetone and formaldehyde withthe steam on and stirring equipment in operation and the material washeated to -125" F. The first portion of caustic soda-water solution wasadded and the steam cut off. As the temperature rises to F. and the coldwater is turned on, an exothermic reaction takes place and thetemperature slowly rises to 200 F. then slowly begins to fall. At 185 F.the second portion of caustic soda-water solution is added whereupon thetemperature again rises to 200 F. Upon cooling to 185 F. the procedureis repeated allowing the temperature to rise and fall between theadditions of caustic sodawater solution and keeping the cold water onthe jacket at all times. The mass is then allowed to cool to F. at whichtime the cold water is shut off. Vacuum is turned on keeping the ventopen. The vent is slowly closed and the steam turned on. Dehydration maybe continued to produce a resin of 75%-l00% solids.

EXAMPLE A2 (One Mole 0f Acetone With Three illoles Formaldehyde) 30parts of acetone 126 parts formaldehyde (37% concentration) 2 parts NaOHin 4 part water The caustic soda-solution was divided into three equalportions. Using the same procedure as that set forth in Example 1, theresultant resinous product produced was amber colored and measured morethan 75% of the combined weights of acetone and formaldehyde in theoriginal charge. The resin was soluble in water.

i? EXAMPLE A3 The following additional example of water solubleketone-aldehyde reaction product and method for making it are given.

120 parts by weight of acetone 340 parts of commercial 37 /2 solution offormaldehyde 4 parts of diethylaminopropyl amine are brought together insteps to control exothermic reaction and after the latter subsides thereaction mass is heated under a condenser and to refluxing temperaturefor /2 hour and then dehydrated to about 70% solids. The resultingproduct is an acetone-formaldehyde reaction product in solution inwater.

In the General Examples A of water soluble ketonealdehyde reactionproducts there can be included those made by substituting a part of theacetone by other ketones and/ or a part of the formaldehyde by otheraldehydes. About 50% of the acetone can be substituted by one or more ofmethyl ethyl ketone, methyl isopropyl ketone, mesityl oxide, diacetonealcohol or others and/or about 50% of the formaldehyde can besubstituted by one or more of acetaldehyde, propinaldehyde,butyraldehyde or others to obtain water soluble ketone-aldehyde reactionproducts suitable for the practice of the present invention.

EXAMPLE B1 A cleaning or pickling solution is made up of the following:

100 parts by weight of water, 25 parts of hydrochloric acid and 12 partsof the material of Example A1.

EXAMPLE B2 A cleaning or pickling solution is made up of the following:

100 parts by weight of water, 10 parts of sulphuric acid and 10 parts ofthe material of Example A1.

Other examples can be made by following Examples B1 and B2 andsubstituting any of the other water soluble ketone-aldehyde reactionproducts given in said US. patent identified above or described hereinin place of all or any part of material of Example Al.

EXAMPLE C1 An example of a chromium plating bath, according to thepresent invention, is as follows:

100 parts by weight of water, 25 parts of chromic acid, sulphuric acidin amount to make the ratio of chromic acid to S0,, to be 100:1, and 10parts of the material of Example A1.

EXAMPLE C2 For a copper plating bath the following is made up: 100 partsby weight of water, 4 parts of copper metal, 5 parts of sulphuric acidand 8 parts of the material of Example A1.

Other examples can be made by following the formulas of Examples C1 andC2 and substituting any of the other water soluble ketone-aldehydematerials given in said US. patent identified above or described hereinin place of all or any part of material of Example A1.

EXAMPLE D To 100 parts by weight of a sulphuric acid-water solution ofspecific gravity from 1.200 to 1.300, 10 parts of the material ofExample A1 are added and any of the other Water-soluble ketone-aldehydereaction products described in said US. Patent 2,683,133 or definedherein (1 can be used in place of all or any part of said material ofExample A1.

EXAMPLE E In a dry cell battery comprising a containing negativeelectrode of zinc and a carbon rod as a positive electrode and a watersolution of sal ammoniac and zinc chloride mixed into a depolarizercomprising powdered coke, graphite and manganese dioxide, the materialof Example A1 is added to enhance the function of the depolarizer andthe addition is made in amount by weight about /2 to 10% of the salammoniac and zinc chloride.

While Water has been stated as being the solvent in the baths andsolutions of the present invention, variation thereof may be made byadding thereto other liquids such as alcohols (ethyl, methyl, propylalcohol, for examples) in accordance with general practice known tothose skilled in the art; also electrolytes other than those recited canbe added to the materials recited in the examples hereof, such as forexample as ammonia compounds and nitro compounds (ammonium sulphate,nitrobenzene) without departing from the spirit of the invention.

Although I have indicated in specific examples that the mole ratio ofaldehyde to ketone in the formation is 2 to 4 moles of aldehyde to onemole of ketone, it is considered that the present invention is operativewhen using water soluble reaction product made from 2 to 6 moles ofaldehyde to one mole of ketone by the methods given for the morespecific examples, and these reaction products as used in the practiceof the present invention are those which in the presence of acids aresoluble in water to the amount of /2.% to 30% of the water by weight,and the acids are used in amount from /2% to 35% of the water.

Having thus described my invention, what I claim is:

The method for cleaning a surface of a metal element comprisingsubjecting said element to an aqueous solution of an inorganic acidcapable of cleaning a surface of said element, said solution containinga water-soluble acetoneformaldehyde reaction product in an amountsufficient to protect said element from deleterious action of saidinorganic acid which would otherwise occur, said reaction productproduced by reacting under alkaline conditions acetone and formaldehydein the mole ratio of 1 mole of acetone to 2-6 moles of formaldehyde.

References Cited in the file of this patent UNITED STATES PATENTS1,470,225 Holmes Oct. 9, 1923 1,716,542 Ellis June 11, 1929 2,049,517Saukaitis Aug. 4, 1936 2,152,406 Ducamp Mar. 28, 1939 2,259,169 LittleOct. 14, 1941 2,666,738 Kardos Ian. 19, 1954 2,683,133 Harvey et a1.July 6, 1954 2,711,971 Miller et al. June 28, 1955 2,733,198 Nobel et alIan. 31, 1956 2,758,970 Saukaitis et al Aug. 14, 1956 2,766,218 Harveyet a1 Oct. 9, 1956 FOREIGN PATENTS 810,779 France Jan. 6, 1937 1,114,697France Dec. 19, 1955 346,162 Great Britain Apr. 9, 1931 OTHER REFERENCESCorrosion Handbook, by Uhlig, pages 910-912, John Wiley, New York 1948).

